a) Field of the Invention
The present invention relates to an electronic-part surface mounting apparatus. More particularly, the invention relates to an electronic-part surface mounting apparatus of the multi-shaft absorption head type which successively mounts a plural number of mounted parts, for example, electronic parts, through absorption to one mounter head.
b) Description of the Related Art
A conventional electronic-part surface mounting apparatus includes: a mounter head having a single Z-shaft with an absorption nozzle firmly attached to the end thereof, the Z-shaft being vertically movable with respect to a mounted surface and rotatable in a plane parallel to the mounted surface; and a table bearing a printed circuit board thereon being fixed or moved in the X and the Y direction. The table is operated such that when the mounter head is moved in the X and the Y direction, the printed circuit board is fixed, while when the mounter head is fixed, the printed circuit board is moved in the X and the Y direction.
To deal with a situation where a plural number of mounted parts are picked up from a plural number of part supply means and mounted on the mounted surface of a printed circuit board, the electronic-part surface mounting apparatus is designed to have an array of a plural number of mounter heads arranged side by side.
In the electronic-part surface mounting apparatus which uses the mounter heads arranged side by side, the machine size is inevitably increased. Further, the mounter head is large compared with the part supply means which may closely be arranged side by side. Therefore, when a plural number of mounter heads are arranged in a limited space, for example, only every other mounted part can be attracted and held. In other words, it is impossible to perform simultaneous attraction by all the mounter heads. Accordingly, considerable time is taken for attracting and holding the mounted parts. Further, the distance between two adjacent mounter heads of the array of those heads arranged side by side exceeds the coverage of one camera. Therefore, a camera for recognizing the position of the mounted part must be used for each of the mounted parts attached.